package com.lagou.client;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import com.lagou.handler.StringChannelHandler;
import com.lagou.handler.UserClientHandler;
import com.lagou.request.RpcRequest;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * 消费者
 */
public class RPCConsumer {

    // 1.创建一个线程池对象 -- 它要处理我们自定义事件
    private static ExecutorService executorService =
        Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    // 2.声明一个自定义事件处理器 UserClientHandler
    private static UserClientHandler userClientHandler;

    // 3.编写方法,初始化客户端 ( 创建连接池 bootStrap 设置bootstrap 连接服务器)
    public static void initClient() throws InterruptedException {
        // 1) 初始化UserClientHandler
        userClientHandler = new UserClientHandler();
        // 2)创建连接池对象
        EventLoopGroup group = new NioEventLoopGroup();
        // 3)创建客户端的引导对象
        Bootstrap bootstrap = new Bootstrap();
        // 4)配置启动引导对象
        bootstrap.group(group)
            // 设置通道为NIO
            .channel(NioSocketChannel.class)
            // 设置请求协议为TCP
            .option(ChannelOption.TCP_NODELAY, true)
            // 监听channel 并初始化
            .handler(new StringChannelHandler(userClientHandler));

        // 5)连接服务端
        bootstrap.connect("127.0.0.1", 8999).sync();
    }

    // 4.编写一个方法,使用JDK的动态代理创建对象
    // serviceClass 接口类型,根据哪个接口生成子类代理对象; providerParam : "UserService#sayHello#"
    public static Object createProxy(Class<?> serviceClass, final RpcRequest rpcRequest) {
        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class[] {serviceClass},
            new InvocationHandler() {
                public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
                    // 1)初始化客户端cliet
                    if (userClientHandler == null) {
                        initClient();
                    }
                    // 2)给UserClientHandler 设置param参数
                    userClientHandler.setRpcRequest(rpcRequest);

                    // 3).使用线程池,开启一个线程处理处理call() 写操作,并返回结果
                    Object result = executorService.submit(userClientHandler).get();
                    // 4)return 结果
                    return result;
                }
            });
    }

}
